this is an offensive team that the defense department would use to defend the nation if it were attacked in cyber space. joining me now from washington to discuss the developing battle ground david sanger of the "new york times." welcome. >> great to be back with you. >> tell me why security experts are saying this has become if not our biggest national security threat the one emerging with the most concern for them. >> well it's certainly our newest and it may be among the urge else as it's an issue of consider debate. it's urgent because there are cyber attacks on the united states, mostly on u.s. corporations that take place every single day. but these are mostly attacks to sweep up vast amounts of intellectual property. whether it's an automobile design, the design of a gas pipeline, could be any kind of commercial information that chinese or other companies might find useful. that isn't really at the center of the biggest national security concern. the biggest national security concern is what happens if a foreign power or a foreign hacker, a non-state actor manages to get into crit